使用JNI的步骤

public class WitWrapper {

    static {
        System.loadLibrary("witengine");
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        new WitWrapper().run();
    }

    private void run() {
        solve("C:\\temp\\witlib\\problem.txt");
    }

    public native static int solve(String filename);
}

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class XXX_WitWrapper */

#ifndef _Included_XXX_witwrapper_WitWrapper
#define _Included_XXX_witwrapper_WitWrapper
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     XXX_WitWrapper
 * Method:    solve
 * Signature: (Ljava/lang/String;)I
 */
JNIEXPORT jint JNICALL Java_XXX_WitWrapper_solve
  (JNIEnv *, jclass, jstring);

#ifdef __cplusplus
}
#endif
#endif 

/**************************************************************************** 
 *
 * Sample WIT API Program.
 * Runs implosion on the Diner problem.
 *
 ****************************************************************************/
#include <stdlib.h>
#include "wit.h"
#include "jni.h"

/****************************************************************************/
/* Main Program                                                             */
/****************************************************************************/
JNIEXPORT jint JNICALL Java_XXX_WitWrapper_solve
  (JNIEnv * env, jclass jc, jstring file)
{
  WitRun * theWitRun;
  const char *str = (*env)->GetStringUTFChars(env, file, 0);//把jstring转换为char *，否则会有错
  printf(str);

   /* Initialize WIT */
   witNewRun( &theWitRun );
   witInitialize ( theWitRun );

   witReadData (theWitRun, str);
   /*************************************************************************
    *
    * Finished entering data
    *
    ************************************************************************/

   witOptImplode( theWitRun );
   witWriteExecSched( theWitRun, "execsched.txt", WitBSV );
   witWriteShipSched( theWitRun, "shipsched.txt", WitBSV );


   witDeleteRun( theWitRun );

   exit (0);

} /* main */